如何通过数据绑定在viewModel和MainActivity之间进行通信？

android {
    ...
    dataBinding {
        enabled = true
    }
}

<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="viewModel"
            type="com.example.ViewModel" />
    </data>
    
    <!-- 布局内容 -->
    
</layout>

public class MainActivity extends AppCompatActivity {
    private com.example.ViewModel viewModel;
    private com.example.databinding.ActivityMainBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        // 使用DataBindingUtil类绑定布局文件和MainActivity
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        
        // 创建viewModel实例
        viewModel = new com.example.ViewModel();
        
        // 设置viewModel
        binding.setViewModel(viewModel);
        
        // 更新视图
        binding.executePendingBindings();
    }
}

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@{viewModel.text}" />